SWFO Ground Segment

The SWFO Antenna Network (SAN) is a globally distributed antenna network that provides continuous coverage for SWFO-L1 data acquisition. Dual S- and X-band ground antennas will be located at WCDAS in Wallops, VA and at CBU in Fairmont, WV. X-band only antennas will be located around the world to complete the global coverage enabling continuous downlink of space weather observational data. Data will be transmitted from the SAN to Command and Control (C2). The SAN is being procured by NOAA.

Commanding of SWFO-L1 will be done from the NOAA Satellite Operations Facility (NSOF) in Suitland, MD with uplink capability at Wallops Command and Data Acquisition Station (WCDAS) in Wallops, VA (primary) and at the Consolidated BackUp facility (CBU) in Fairmont, West Virginia (backup). Command and Control supports the SWFO-L1 Mission with mission planning, spacecraft control, observatory command and telemetry, observational data acquisition and data routing. Space weather observational data received by C2 from the SAN is sent from C2 to the Space Weather Prediction Center (SWPC) in Boulder. The SAN is being procured by NOAA

The SWFO Program will make available a number of space weather products for NOAA’s users. SWFO will implement the data processing, algorithm development, calibration/validation, and data product distribution through NWS’s Space Weather Prediction Center (SWPC) and NESDIS’s National Centers for Environmental Information (NCEI). Operations-based products will be developed by NWS Space Weather Prediction Center (SWPC) for real time use by the center’s forecasters and other operational users. The NESDIS National Centers for Environmental Information (NCEI) will develop science- based products and provide long-term archiving and data stewardship for retrospective users.

The products include coronal images in visible light which are typically immediately usable as inputs in the inner boundary condition of heliospheric simulations. In addition, higher-level products for coronal mass ejection (CME) properties can be derived from the coronal images. These are CME speed, direction, time of arrival at 21.5 R Sun , size, and mass. These products will be developed from CCOR images obtained by SWFO-L1 and GOES-U. Products from in situ measurements include properties of the solar wind plasma, such as density, velocity, temperature, and pressure, and of the interplanetary magnetic field. Several of these are used as real-time inputs to numerical weather prediction (NWP) models at SWPC. Products obtained from the suprathermal particle differential flux will be used for higher-precision estimates of arrival times for CMEs and other geoeffective structures. Higher-order products will be developed by SWPC and NCEI which include species-related properties, for instance densities calculated separately for protons, helium ions, and electrons.

From a coronagraph image, an Earth-directed CME is viewed as a radially expanding circle of enhanced brightness centered on the sun. The speed and direction of the CMEs is obtained from two or more CME time-lapse images showing the radial expansion of the CME circle. A CME plasma density increase is observed by the detection of solar photons that are Thomson-scattered by coronal plasma electrons. The CME mass is proportional to the scattered photons. Models use the images of CMEs to refine estimates of CME arrival time. However, with only the CME images, intensity of the impending geomagnetic storm is not yet known. Forecasters issue a watch that something is coming in 12-18 hours. The magnetic strength and orientation are needed to determine how the CME will couple with the Earth’s magnetosphere. Solar wind data at L1, 92 million miles from the Sun but still 1 million miles upstream of Earth, provide the measurements of the needed solar wind velocity and magnetic field strength and direction. With these data, forecasters can determine the strength of the storm headed to Earth, 15 and up to several tens of minutes prior to arrival and issue the warning.